use anyhow::Result;
use std::path::PathBuf;
use tokio::fs as async_fs;
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use shared::types::User;

pub struct FileOperations {
    // 文件操作实现
}

impl FileOperations {
    pub fn new() -> Self {
        Self {}
    }
    
    /// 读取文件内容
    pub async fn read_file(&self, path: &PathBuf) -> Result<Vec<u8>> {
        let mut file = async_fs::File::open(path).await?;
        let mut contents = Vec::new();
        file.read_to_end(&mut contents).await?;
        Ok(contents)
    }
    
    /// 写入文件内容
    pub async fn write_file(&self, path: &PathBuf, contents: &[u8]) -> Result<()> {
        let mut file = async_fs::File::create(path).await?;
        file.write_all(contents).await?;
        file.flush().await?;
        Ok(())
    }
    
    /// 追加文件内容
    pub async fn append_file(&self, path: &PathBuf, contents: &[u8]) -> Result<()> {
        let mut file = async_fs::OpenOptions::new()
            .create(true)
            .append(true)
            .open(path)
            .await?;
        file.write_all(contents).await?;
        file.flush().await?;
        Ok(())
    }
    
    /// 流式读取文件
    pub async fn stream_read_file(&self, path: &PathBuf) -> Result<async_fs::File> {
        let file = async_fs::File::open(path).await?;
        Ok(file)
    }
    
    /// 流式写入文件
    pub async fn stream_write_file(&self, path: &PathBuf) -> Result<async_fs::File> {
        let file = async_fs::File::create(path).await?;
        Ok(file)
    }
    
    /// 获取目录列表
    pub async fn list_directory(&self, path: &PathBuf) -> Result<Vec<DirEntry>> {
        let mut entries = Vec::new();
        let mut dir = async_fs::read_dir(path).await?;
        
        while let Some(entry) = dir.next_entry().await? {
            let path = entry.path();
            let metadata = entry.metadata().await?;
            
            entries.push(DirEntry {
                name: path.file_name()
                    .and_then(|n| n.to_str())
                    .unwrap_or("")
                    .to_string(),
                is_directory: metadata.is_dir(),
                size: if metadata.is_file() { Some(metadata.len()) } else { None },
                modified: metadata.modified()?.into(),
            });
        }
        
        Ok(entries)
    }
    
    /// 复制文件
    pub async fn copy_file(&self, from: &PathBuf, to: &PathBuf) -> Result<()> {
        async_fs::copy(from, to).await?;
        Ok(())
    }
    
    /// 移动文件
    pub async fn move_file(&self, from: &PathBuf, to: &PathBuf) -> Result<()> {
        async_fs::rename(from, to).await?;
        Ok(())
    }

    /// 获取文件修改时间
    pub async fn get_file_modified_time(&self, path: &PathBuf) -> Result<std::time::SystemTime> {
        let metadata = async_fs::metadata(path).await?;
        Ok(metadata.modified()?)
    }

    /// 检查文件是否存在
    pub async fn file_exists(&self, path: &PathBuf) -> bool {
        async_fs::metadata(path).await.is_ok() && async_fs::metadata(path).await.unwrap().is_file()
    }

    /// 检查目录是否存在
    pub async fn directory_exists(&self, path: &PathBuf) -> bool {
        async_fs::metadata(path).await.is_ok() && async_fs::metadata(path).await.unwrap().is_dir()
    }

    /// 创建目录
    pub async fn create_directory(&self, path: &PathBuf) -> Result<()> {
        async_fs::create_dir_all(path).await?;
        Ok(())
    }

    /// 删除目录
    pub async fn delete_directory(&self, path: &PathBuf) -> Result<()> {
        async_fs::remove_dir(path).await?;
        Ok(())
    }

    /// 删除文件
    pub async fn delete_file(&self, path: &PathBuf) -> Result<()> {
        async_fs::remove_file(path).await?;
        Ok(())
    }

    /// 重命名文件或目录
    pub async fn rename(&self, from: &PathBuf, to: &PathBuf) -> Result<()> {
        async_fs::rename(from, to).await?;
        Ok(())
    }
}

/// 目录条目
#[derive(Debug, Clone)]
pub struct DirEntry {
    pub name: String,
    pub is_directory: bool,
    pub size: Option<u64>,
    pub modified: std::time::SystemTime,
}
